Require Members to live in Canada to checkout for a specific level.

my_pmpro_require_canada_level_8.php

/**
 * Require Members to live in Canada to checkout for a specific level.
 */
function my_pmpro_require_canada_level_8( $value ) {
	global $pmpro_level;
    
    $bcountry = $_REQUEST['bcountry'];
	
	if ( ( $pmpro_level->id == '8' ) && ( $bcountry != 'CA' ) )  {
		global $pmpro_msg, $pmpro_msgt;
		$pmpro_msg = "This level is only available to members living in Canada.";
		$pmpro_msgt = "pmpro_error";
		$value = false;
	}
	
	return $value;
}
add_filter( 'pmpro_registration_checks','my_pmpro_require_canada_level_8', 10, 1 );